Structural panel

ABSTRACT

A structural panel including an open core frame covered by skin elements to form the panel. The frame is made up of I-beams which are connected together with an interlock to form joints. One of the I-beams in each joint has a tongue which fits between the flanges of the other I-beam and is notched to receive a retaining rib of the interlock. A lip on the flange retains the interlock in place.

0 United States Patent 1 1 1111 3,780,485 Matson Dec. 25, 1973STRUCTURAL PANEL 3,268,260 8/1966 Snipe 287/53 TK [7 e o Ro ert P. atsonP'O. Box 9986, 3,664,011 5/1972 Labastrou 287/2092 K Atlanta, Ga. 30306FOREIGN PATENTS OR APPLICATIONS 22 Filed; 22 1972 592,606 9/1947 GreatBritain 287/2092 K [21] Appl' 227883 Primary Examinerl-lenry C.Sutherland Attorney-B. .1. Powell [52] US. Cl 52/665, 52/585, 52/615,

287/2092 K, 287/l89.36 A 57 ABSTRACT [51 Int. Cl. E04c 2/42, E04c 5/04[58] Field 61 Search 287/54 c, 56, 189.36 A, A Structural Panel frame Y'287/209 ZK 20 92 D 53 TK 53 ered by skin elements to form the panel. Theframe 1s 52/585 6 665 6 made up of l-beams which are connected togetherwith an interlock to form joints. One of the l-beams in [56] ReferencesCited each joint has a tongue which fits between the flanges of theother l-beam and is notched to receive a retain- UNITED STATES PATENTSing rib of the interlock. A lip on the flange retains the 2,931,4684/1960 Keller 52 664 t 1 k l 610,576 9/1898 Auger 287/53 LK m er 00 m pac 1,453,822 5/1923 Zeman 287/189.36 A 5 Claims, 6 Drawing FiguresPATENIEU 05:25 1973 SHEET 2 BF BACKGROUND OF THE INVENTION Various kindsof structural panels are available on the market today. Such panelsgenerally have an open core framework covered by skin members onopposite sides thereof. These prior art panels have very simple jointsconnecting the members in the framework in an attempt to reduce themanufacturing cost of the panel. The use of these joints, however, haslimited the joint strength so as to reduce the load carrying capabilityof the panel. Moreover, the simplicity of the joint construction haslimited the versatility of the joint thereby limiting the use of thepanel to relative simple structures or relative simple portions of morecomplex structures.

SUMMARY OF THE INVENTION These and other problems and disadvantagesassociated with the prior art are overcome by the invention disclosedherein by providing a structural panel having sufficient joint strengthto carry a bearing load. Moreover, the joint construction is relativesimple so as to permit the panel to be economically manufactured.Because the beams forming the open grid framework of the panel can beplaced in position and then locked in place without further movement ofthe beams relative to each other, the relative angles between beams of aparticular joint can be varied to provide for panels having greaterversatility as to overall shape.

The panel of the invention uses I-shaped beams for the interior opengrid framework which is closed by outer sheets of material to form thepanel. The open framework is provided by extending the web portions ofcertain of the I-beams and positioning the protruding web portionbetween flanges of another of the I-beams. An interlocking member isthen used to lock the I- beams with respect to each other to form thejoint. When the open framework is completed, the sheet material isattached to both sides of the framework to complete the panel.

These and other features and advantages of the invention will becomemore clearly understood upon consideration of the followingspecification and accompanying drawings wherein like characters ofreference designate corresponding parts throughout the several views andin which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of astructural panel embodying the invention;

FIG. 2 is an exploded perspective view of part of the panel of FIG. 1;

FIG. 3 is an enlarged cross-sectional view taken along line 3-3 in FIG.1;

FIG. 4 is a cross-sectional view taken along line 4--4 in FIG. 3;

FIG. 5 is a view similar to FIG. 4 showing an alternate jointconstruction; and

FIG. 6 is a side view of an alternate embodiment of the interlock.

These figures and the following detailed description disclose specificembodiments of the invention, how ever, it is to be understood that theinventive concept is not limited thereto since it may be embodied inother forms.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS Referring to FIGS. 1-4,the structural panel 10 embodying the invention includes an open gridframework 11 covered on opposite sides by sheets of material 12. Thisproduces a strong lightweight panel.

The framework 11 is formed of l-beams 14, some of which extend throughthe panel as stringers l5 and some of which extend betwen stringers 15as connectors 16 to form joints 13. All of the I-beams 14 have the samecross-sectional shape with a central web 18, and a pair of flanges 19along opposite edges of web 18 and extending outwardly therefromgenerally perpendicular to web 18. The outermost edges of each flange 19is provided with an integral inwardly turned lip 20 to form alongitudinally extending recess 21 between the web facing surface 22 oflip 20 and the web 18.

For locking the connectors 16 to the stringers 15 in any selectedlocation to form joint 13, an interlock 25 is provided. The interlock 25has an elongated main body 26 with a cross-sectional shape adapted to beslidably received in the recess 21 between the lip 20 and web 18 of thestringer 15. A retaining rib 28 is integral with the body 26 along itslength and protrudes within the opening 24 between the innermost edgesof opposite lips 20 when the body 26 is received in the recess 21.

The end of each connector 16 is formed to fit within the opening 24betwen the lips 20 and to be engaged by the interlock 25 to be held inplace. This is done by removing the flanges 19 from the end of theconnector 16 a prescribed distance d equal to the depth d of the opening24 from the outer surface 29 of lip 20 to the surface of web 18 andnotching the edges of web 18. This provides a tongue 30 on web 18 whichprotrudes the distance d, beyond the ends of flanges 19 on connector 16and which has a width w, to allow passage of the tongue 30 into opening24 and abut web 18. A notch 32 is provided in the opposite edges of thetongue 30 which receives the rib 28 therethrough.

When the interlocks 25 are holding the tongue 30 and connector 16 inplace, it will be seen that the abutment surface 31 of the body 26 abutsthe web facing surface 22 of lip 20, the outer locking surface 33 ofbody 26 engages the inner surface 34 of flange 19 in recess 21, and theinner surface 35 of body 26 engages the outer side edge 36 of the tongue30. The engagement of the surfaces of the body 26 with the lip 20,flange l9 and tongue 30 maintains the interlock 25 in place while at thesame time causing the connector 16 to be held in place by the rib 28.

The connectors 16 may be joined with the stringers 15 using theinterlocks 25 by first positioning the interlock in the recess 21 ofstringer l5 and twisting the connector 16 about its longitudinal axis tocause the notches 32 in the tongue 30 to be engaged by rib 28. Also, thetongues 30 of connectors 16 may be first located in the opening 24 andthen the interlocks 25 inserted in recesses 21 so that the ribs 28thereof engage the notches 32.

When the connector 16 has a longitudinally directed external forceexerted therethrough so as to tend to pull the tongue 30 out of opening24, a moment of force will be exerted on the bodies 26. This causes theinner surfaces 35 of bodies 26 to exert opposed forces on the edges 36of tongue 30 to tightly clamp the tongue 30 therebetween and relieve theshear forces on rib 28. This effectively distributes the bearing loadover a larger area with a corresponding reduction in the material stresslevel of the joint 13.

The interlock 25 is illustrated in FIGS. 3 and 4 as having constantdimensions along its length which is approximately the total thicknessof beam 14 including the flanges 19. It is to be understood the lengthmay be varied as shown in FIG. 2 without departing from the scope of theinvention. Further, the location of the rib' 28 across the width of thesurface 35 may be changed without departing from the scope of theinvention.

FIG. 6 shows an alternate embodiment of the interlock and is designated125. The interlock 125 is wedged into position and includes a body 126like body 26 as well as a locking rib 128. The rib 128 is tapered withrespect to its thickness 1, but not with respect to its width. Thus,when the interlock 126 is inserted into recess 21, the rib 128 is wedgedinto the notch 32 in tongue 30 to lock the joint 13 together.

The joints 13 illustrated in FIGS. 1-4 locate the stringers 15 andconnectors 16 normal to each other. The use of the interlocks or 125allow the joint to be made when the connectors 16 and stringers 15 arenot perpendicular. Such a joint is shown in FIG. 5 and designated 13'.Joint 13 is identical to joint 13 except that the angle a of the endsurface 40 of flange 19 is not 90 as is the case with joint 13. Also,the notch 32 in tongue is either wider as shown or cut through tongue 30at the same angle a as the surface of flange 19. Thus, the versatilityof the joint and panel 10 is greatly increased.

After all of the joints 13 have been made to complete the framework 11,the sheets 12 are attached to the outermost surfaces 41 of flanges 19 byknown means such as an adhesive or bonding agent. The sheets 12 may bemade of any materials such as wood, metal or plastic and serve tocomplement the frame 11 to form a strong lightweight panel 10.

While specific embodiments of the invention have been disclosed herein,it is to be understood that full use of modifications, substitutions andequivalents may be made without departing from the scope of theinventive concept.

I claim:

1. A structural building panel comprising a plurality of beam elementsinterlocked together to form an open grid frame, all of said elementshaving substantially the same cross-sectional configuration including acentral web having opposed longitudinally extending edges, at least onelongitudinally extending flange integral with each opposed edge of saidcentral web and extending outwardly therefrom substantiallyperpendicular to said central web, said flanges opposed to each otherand projecting outwardly from the same side of said central web, and aretaining lip integral with each projecting edge of said flanges andextending longitudinally therealong substantially parallel to saidcentral web, said lips extending inwardly toward each other over saidcentral web to define a prescribed opening between the innermost edgesthereof, an inwardly opening longitudinally extending recess definedbetween the opposed surfaces of said central web and each of said lipsand the inside surface of each of said flanges, said lip defining anouter abutting surface along the length thereof, a cutout defined inopposite corners of the ends of certain of said beam elements defining aprojecting tongue in said central web, said cutouts having a lengthsubstantially equal to the distance from said central web to the outerabutting surface of said lip and a width substantially equal to thedistance between the innermost edge of said lip and the outside surfaceof said flange so that the projecting end of said tongue is justslidably received through said opening between said lips on another ofsaid beam elements and the ends of said flanges at said cutouts on saidcertain beam element abuts said outer abutting surface of said lips ofsaid when the projecting end of said tongue substantially abuts saidcentral web of said, an inwardly extending notch defined in oppositesides of said tongue and opening into said cutout, each of said notchesspaced from the ends substantially said flanges at said cutout adistance substantailly equal to the thickness of said lip; and, aninterlock received through each of said cutouts in said certain beamelement and within said recess of said another beam element to lock saidcertain beam element onto said another beam element, each of saidinterlocks including an elongate main body having a generally squarecross-sectional shape and slidably received within said recess with thatside of said main body facing said tongue abutting the edge of saidtongue at said cutout, and a retaining rib integral with said main bodyat that corner adjacent said notch and extending into said notch so thatas a separation force is applied to said beam elements to pull saidtongue from between said lips, said retaining lip rotates said main bodyof said interlock into binding engagement with said tongue and theinside surface of said flange of said another beam element to lock saidbeam elements together.

2. The panel of claim 1 wherein said retaining rib tapers in thicknessalong its length with one end thinner than the width of said notch andone end thicker than the width of said notch.

3. The panel of claim 1 wherein that surface of said flanges and saidlips at said cutout defines a prescribed included angle with saidcentral web of said certain beam element.

4. The panel of claim 3 wherein said prescribed included angle issubstantially 5. The panel of claim 1 further including a skin elementcovering opposed sides of said open grid frame.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,78O,L85 Dated December 27, 1973.

Inventofls) RObert P. MatsOn It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column LL, lines 21 and 22, "when the projecting end [of said tonguesubstantially abuts said central web of said should read another beamelement Column L line 25, "substantially" should read of Column ll, line25, "substantailly" should read substantially Signed and sealed this30th dayv of April 1971;.

(SEAL) Attest: I

EDI'IAHD M .FLET CID-3R J R. l C MAR SHALL DAMN Attesting OfficerCommissioner of Patents FORM o-wsg (10-69) USCOMM'DC 503764 69 N U.SGOVERNMENT PRINTING OF FICE: Hi9 0-366-334,

1. A structural building panel comprising a plurality of beam elementsinterlocked together to form an open grid frame, all of said elementshaving substantially the same cross-sectional configuration including acentral web having opposed longitudinally extending edges, at least onelongitudinally extending flange integral with each opposed edge of saidcentral web and extending outwardly therefrom substantiallyperpendicular to said central web, said flanges opposed to each otherand projecting outwardly from the same side of said central web, and aretaining lip integral with each projecting edge of said flanges andextending longitudinally therealong substantially parallel to saidcentral web, said lips extending inwardly toward each other over saidcentral web to define a prescribed opening between the innermost edgesthereof, an inwardly opening longitudinally extending recess definedbetween the opposed surfaces of said central web and each of said lipsand the inside surface of each of said flanges, said lip defining anouter abutting surface along the length thereof, a cutout defined inopposite corners of the ends of certain of said beam elements defining aprojecting tongue in said central web, said cutouts having a lengthsubstantially equal to the distance from said central web to the outerabutting surface of said lip and a width substantially equal to thedistance between the innermost edge of said lip and the outside surfaceof said flange so that the projecting end of said tongue is justslidably received through said opening between said lips on another ofsaid beam elements and the ends of said flanges at said cutouts on saidcertain beam element abuts said outer abutting surface of said lips ofsaid when the projecting end of said tongue substantially abuts saidcentral web of said, an inwardly extending notch defined in oppositesides of said tongue and opening into said cutout, each of said notchesspaced from the ends substantially said flanges at said cutout adistance substantailly equal to the thickness of said lip; and, aninterlock received through each of said cutouts in said certain beamelement and within said recess of said another beam element to lock saidcertain beam element onto said another beam element, each of saidinterlocks including an elongatE main body having a generally squarecross-sectional shape and slidably received within said recess with thatside of said main body facing said tongue abutting the edge of saidtongue at said cutout, and a retaining rib integral with said main bodyat that corner adjacent said notch and extending into said notch so thatas a separation force is applied to said beam elements to pull saidtongue from between said lips, said retaining lip rotates said main bodyof said interlock into binding engagement with said tongue and theinside surface of said flange of said another beam element to lock saidbeam elements together.
 2. The panel of claim 1 wherein said retainingrib tapers in thickness along its length with one end thinner than thewidth of said notch and one end thicker than the width of said notch. 3.The panel of claim 1 wherein that surface of said flanges and said lipsat said cutout defines a prescribed included angle with said central webof said certain beam element.
 4. The panel of claim 3 wherein saidprescribed included angle is substantially 90*.
 5. The panel of claim 1further including a skin element covering opposed sides of said opengrid frame.